Diaphragm and method of making the same



May 13. 1924. 1,493,631

v N. H. HOLLAND DIAPHRAGM AND METHOD OF MAKING THE vIYME' Filed Nov. 28 1921 Patented May 13, 1924.

DIAPHRAGM AND METHOD OF MAKING THE SAME.

Application filed November 28, 1921.

To all whom it may concern: Be it lmown that I, NEWMAN H. HOLLAND,

a subject of the King of Great Britain, re-

Sldll'lg at West. Orange, in the county of I Essex,-State of certain new and Diaphragms and Methods New Jersey, have invented useful Improvements in of Making the Same, of which the following is a full, clear, concise, and exact description.

- particularly This invention relates to diaphragms and to those intended to be used for acoustical purposes.

An object of the invention is to provide an acoustical diaphragmof light mass and of uniform structure.

Another object is to provide a process of making ligh t diaphragms which is comparatively inexpensive and one by which the characteristics of the product may be accurately controll Other b 0 invention, electro-deposited formed by electro-depositing a disc consisting of a dissimilar material, plating, leaving the the ring.

The adva ects appear hereinafter.

In general, comprises an diaphragm, preferably metal on a metal ring and a core of which is removed after diaphragm attached to ntages of extremely light dia- 30 phragms are'recognized in the gut of sound reproduction but the difficulty of u orm pro oat d ensive.

35 ight diaphi metal, howe duced which and the diflicul amaging has made their use Heretofore, the most successful ling metal very thin.

obtaining duct and of handling them with very oxaglns have been those made by in working the ver. internal stresses are intro cause warping. In view of this ties which mounting such diaphmgms, it has been nec essary to pr ing and ten sired characteristics.

ness of such mechanical strength being tensioned sullicien ovide special means for clamp- Sioning them to obtain the dc- Necossarily the thickdia phragms is controlled by the required to permit its tly to remove an warping and regional strains, Whereas diap ragms in accordance with the present invention need be only of suflicient thickness to sup parts t at m ort their own Weight or that of any ay be mo unted thereon.

In the drawings, Fig. 1 represents a complete diaphr agm, part of which is in section.

are experienced in.

Serial No. 518,254.

Figs. 2, 3 and 4' represent diflerent stages in the process of making the dia hragm.

Figs. 5 and 6 re resent modified forms in cross section.

In the process of'making in accordance with the invention, 7 has its opening closed by a filler 10 which may be either conductive in itself or have its surface coated with some conducting material. One surface of the filler and the ring is prepared in the usual manner for electroplating, the face of ring 7 and the face 16 of filler 10 being flush. The assembly, shown in Fig. 3, is then placed in a suitable plating bath and a continuous plate covering the surface 15 and 16 is deposited by any well known electro-plating process and the thickness of the plate re ulated in the usual manner. After the plating is completed, the filler 10 is removed leaving the diaphragm 8 attached to ring 7 as in Fig. 1.

Fig. 5 shows a modification in which an electrode 11 is attached to the. diaphra in the platingprocess, the electrode 11 eing embedded in the filler so as to be flush with the diaphragm receiver, the

phraEm intended for use on a magnetic material or exaggerated in Fig. 6 by plates 12, 13 and 14.

It is evident therefore, that diaphragms having practically any desired characteristics may be obtained simply by controlling the plating process. The accuracyiund the facility with which the plating process may be controlled makes it. possible to produce diaphragms of more nearly identical characteristics than can be produced by any other known method. This invention therefore, eliminates the difliculties which have heretofore been experienced in making extremely thin diaphragms.

While a flat diaphragm is shown in the drawing for the purpose of illustrating the invention, it is obvious that diaphragms of any desired shape such as conical or corrugated, may be made by forming the surface of the filler to correspond to the shape dediasired. It has also been found convenient to permit the platin to extend over the marginal surface of t e ring instead of only on the front surface as shown. However, this is a detail which may be controlled in a well known manner in the plating process.

What is claimed is:

1. A dia hragm comprising an annular member and a sheet of thin material electrolytically attached thereto closing the opening therein.

2. An acoustical diaphra comprising an annular member, a secon member'within said annular member, and a sheet of thin metal electrolytically attached to both memhers.

3. An acoustical diaphragm comprisin an annular member, a second member, one ace of each member lying in the same plane and in concentric. relation, and an electrolate deposit on each member continuous t erebetween.

4. The process of making an acoustial dia' phragm which consists in the plating of an annular member and a conducting filler in said member, and then removing said filler leaving the plate spanning the opening in said ring. v

5. The process of making an acoustical diaphragm which consists in filling the opening in a ring with a conducting material, preparing one face of the filler and ring so as to present a smooth plane surface, depositing an electro-plate on said surface and then removing said filler leaving the deposited metal across the opening in said ring.

6. The process of making an acoustical diaphragm which consists in filling an annular member with conducting material, em-

bedding in said filler a plate concentric with 40 saidmember, preparing one face of the ring, filler and plate so as to present a smooth plane surface, depositing a metal uniformly on said surface, and then removing said filler leaving said plate across the opening; be

tween said plate and member.

In witness whereof; I hereunto subscribe my name this 23rd day of November A.

NEWMAN H. HOLLAND. 

